Excel Spreadsheets

When to Use

Tool Use When

create_excel_spreadsheet

User asks to create/generate a NEW spreadsheet

modify_excel_spreadsheet

User asks to edit/update an EXISTING spreadsheet

list_my_excel_spreadsheets

User asks what spreadsheets are available

read_excel_spreadsheet

User wants to download or read spreadsheet contents

preview_excel_sheets

Check actual sheet appearance when editing

Workflow

• Before modifying: call preview_excel_sheets to check current layout.

• After creation/modification: call preview_excel_sheets to verify.

• Run tools sequentially (never parallel) to prevent file race conditions.

Professional Formatting

• Font: Arial for all cells unless an existing template specifies otherwise.

• Negative numbers: parentheses format (1,234) — not minus -1,234 .

• Currency: $#,##0 format. Specify units in headers (e.g., "Revenue ($mm)").

• Percentages: 0.0% (one decimal place).

• Years: format as text ("2024" not "2,024" ).

• Zeros: display as "-" using a custom number format.

Example: professional number formatting

from openpyxl.styles import numbers ws['B2'].number_format = '$#,##0' # Currency ws['C2'].number_format = '0.0%' # Percentage ws['D2'].number_format = '#,##0;(#,##0)' # Negative in parentheses ws['E2'].number_format = '@' # Year as text ws['F2'].number_format = '#,##0;(#,##0);"-"' # Zeros as dash

Financial Model Color Coding

When building financial models, apply these conventions:

Color Hex Usage

Blue text 0000FF

Hardcoded inputs and assumptions

Black text 000000

All formulas and calculations

Green text 008000

Links pulling from other worksheets

Yellow background FFFF00

Key assumptions needing attention

from openpyxl.styles import Font, PatternFill ws['B2'].font = Font(name='Arial', color='0000FF') # Blue: input ws['B3'].font = Font(name='Arial', color='000000') # Black: formula ws['B4'].font = Font(name='Arial', color='008000') # Green: cross-sheet link ws['B5'].fill = PatternFill('solid', fgColor='FFFF00') # Yellow bg: key assumption

Images

from openpyxl.drawing.image import Image ws.add_image(Image('file.png'), 'E1')

Code Rules

• Workbook is pre-initialized as wb = Workbook() , active sheet as ws = wb.active (create), or loaded as wb (modify). Do NOT include Workbook() or wb.save() .

• Available libraries: openpyxl, matplotlib, pandas, numpy (seaborn NOT available)

• ALWAYS use Excel formulas, NEVER hardcode calculated values.

• Wrong: ws['B10'] = total

• Right: ws['B10'] = '=SUM(B2:B9)'

• Place assumptions in separate cells, reference them in formulas (e.g., =B5*(1+$B$6) not =B5*1.05 ).

• Avoid circular references.

• Filenames: letters, numbers, hyphens only.

Tool Reference

create_excel_spreadsheet

Create a new Excel spreadsheet using openpyxl code.

Parameter Type Required Description

python_code

str Yes Python code using openpyxl (see Code Rules above)

spreadsheet_name

str Yes Filename without extension (letters, numbers, hyphens only)

Example tool_input:

{ "python_code": "ws.title = 'Sales'\nws['A1'] = 'Quarter'\nws['B1'] = 'Revenue'\nfor i, (q, r) in enumerate(zip(['Q1','Q2','Q3','Q4'], [100,150,130,180]), start=2):\n ws[f'A{i}'] = q\n ws[f'B{i}'] = r", "spreadsheet_name": "quarterly-sales" }

WARNING: Parameter is spreadsheet_name , NOT filename or name .

modify_excel_spreadsheet

Modify an existing spreadsheet and save with a new name.

Parameter Type Required Description

source_name

str Yes Existing spreadsheet name (without .xlsx)

output_name

str Yes New output name (MUST differ from source)

python_code

str Yes Python code to modify the spreadsheet

Example tool_input:

{ "source_name": "quarterly-sales", "output_name": "quarterly-sales-v2", "python_code": "ws = wb.active\nws['B6'] = '=SUM(B2:B5)'" }

list_my_excel_spreadsheets

List all spreadsheets in workspace. No parameters needed.

read_excel_spreadsheet

Retrieve a specific spreadsheet for download.

Parameter Type Required

spreadsheet_name

str Yes

preview_excel_sheets

Get sheet screenshots for visual inspection before editing.

Parameter Type Required Description

spreadsheet_name

str Yes Spreadsheet name without extension

sheet_names

list[str] Yes Sheet names to preview (empty list [] for all sheets)